Radiation Effect on NO, NOS and TGF-beta Expressions In Rat Lung

Oh,  Young Taek; Park,  Kwang Joo; Kil,  Hoon Jong; Ha,  Mahn Joon; Chun,  Mison; Kang,  Seung Hee; Park,  Seong Eun; Chang,  Sei Kyung

J Korean Soc Ther Radiol Oncol > Volume 18(4); 2000 > Article

Original Article

The Journal of the Korean Society for Therapeutic Radiology and Oncology 2000;18(4): 321-328.

Radiation Effect on NO, NOS and TGF-beta Expressions In Rat Lung

Young Taek Oh, Kwang Joo Park, Hoon Jong Kil, Mahn Joon Ha, Mison Chun, Seung Hee Kang, Seong Eun Park, Sei Kyung Chang

¹Department of Radiation Oncology, School of Medicine, Ajou University, Suwon, Korea.
²Department of Pulmonary Medicine, School of Medicine, Ajou University, Suwon, Korea.
³Institute for Medical Sciences, School of Medicine, Ajou University, Suwon, Korea.
⁴Department of Radiation Oncology, Eulji Medical College, Daejon, Korea.

ABSTRACT

PURPOSE:
NOS2 induce NO production and NO activate TGF-beta. The TGF-beta is a inhibitor of NOS2. If this negative feedback mechanism operating in radiation pneumonitis model, NOS2 inhibitor may play a role in TGF-beta suppression. We planned this study to evaluate the expression patterns of NO, NOS2 and TGF-beta in vivo radiation pneumonitis model.
MATERIALS AND METHODS:
Sixty sprague-Dawley rat were irradiated 5 Gy or 20 Gy. They were sacrificed 3, 7, 14, 28 and 56 days after irradiation. During sacrifice, we performed broncho-alveolar lavage (BAL). The BAL fluids were centrifuged and supernatents were used for measure NO and TGF-beta, and the cells were used for RT-PCR.
RESULTS:
After 5 Gy of radiation, NO in BAL fluid increased at 28 days in both lung and TGF-beta in left lung at 56 days. NO increased in BAL fluid at 28 days in both lung after irradiation and TGF-beta in right lung at 28-56 days after 20 Gy of radiation. After 5 Gy of radiation, NOS2 expression was increased in right lung at 14 days, in both lung at 28 days and in left lung at 56 days. TGF-beta expression was reduced in both lung at 28 days and increased in left lung at 56 days.
CONCLUSIONS:
The proposed feedback mechanism of NO, NOS2 and TGF-beta was operated in vivo radiation pneumonitis model. At 56 days, however, NOS2 and TGF-beta expressed concurrently in left lung after 5 Gy and in both lung after 20 Gy of radiation.

Key Words: Radiation pneumonitis, NO, NOS2, TGF-beta, Radiation